In order to effectively reduce product size, micro-electro-mechanical-systems (MEMS) have been developed with better integration and lower cost to meet the recent trend of developing multi-function miniature electronic products.
Capacitive transducers use membranes which sense vibrations generated by pressure variations in various types of MEMS devices, such as MEMS microphones and pressure sensors. Capacitive transducers convert the pressure variation signals to electrical signals, and sense various types of pressure ranges. The sensing mechanism depends on these membranes, and the sensitivity of the MEMS devices can be adversely impacted by their material and structure, which may be easily deformed by ambient temperature and process residual stress variations. When capacitive transducers encounter a large impacting force from a device drop, the sensing membrane can also be damaged, which affects the sensitivity of the MEMS device and the sensing quality.